QQ 

{dy}部分
摘要 ……………………………………………………...3
第二部分
1.设计任务………………………………………………..4
1.1基本要求………………………………………………………….........4
1.2发挥部分……………………………………………………………….4
1.3创新部分……………………………………………………………….4
2．方案论证与比较………………………………………5
2.1 显示部分……………………………………………………………….5
2.2 数字时钟……………………………………………………………….5
2.3 温度采集部分………………………………………………………….6
2.4 芯片选择……………………………………………………………….6
2.5 闹铃方式的选择……………………………………………………….6
2.6 止闹方式的选择……………………………………………………….6
2.7 串口通讯芯片的选择………………………………………………….6
3. 总体方案……………………………………………….7
3.1 工作原理……………………………………………………………….7
3.2 总体设计……………………………………………………………….7
4．系统硬件设计…………………………………………7
4.1  AT89S52单片机最小系统…………………………………………...8
4.2  温度测量模块………………………………………………………...8
4.3  时钟模块……………………………………………………………..8
4.4  键盘模块……………………………………………………………..9
4.5  LED点阵显示模块………………………………………………….10
4.6  电源的选择………………………………………………………….11
4.7  PC机通讯……………………………………………………………12
4.8  整体电路…………………………………………………………….12
5．系统软件设计………………………………………….7
5.1  主程序流程………………………………………………………….13
5.2  扫描子程序………………………………………………………….14
5.3  时间程序…………………………………………………………….15
5.4  PC机串口通讯程序…………………………………………………15
5.5  亮度调节程序………………………………………………………16
5.6  温度程序…………………………………………………………….17
6．测试与结果分析……………………………………...17
6.1  基本部分测试与分析……………………………………………….17
6.2  发挥部分测试与分析……………………………………………….18
6.3  创新部分测试与分析……………………………………………….18
7．设计总结……………………………………………...18
8．参考资料……………………………………………...18
附录……………………………………………………………18
例程…………………………………………………………......................................18

摘要 LED大屏幕显示系统，以AT89S52单片机为核心，由键盘显示、录放音模块、光电开关、温度采集、定时闹铃、LED大屏幕显示等功能模块组成。基于题目基本要求，本系统对时间显示和大屏幕显示进行了重点设计。此外，扩展单片机外围接口、温度采集、非接触式止闹、滚动屏幕显示、语音报时等功能。本系统大部分功能由软件来实现，吸收了硬件软件化的思想，大部分功能通过软件来实现，使电路简单明了，系统稳定性大大提高。本系统不仅成功的实现了要求的基本功能,发挥部分也得到xx的实现,而且有一定的创新功能。 
关键字：单片机   LED大屏幕   滚屏显示
Abstract  This large LED display screen system ,based on chip microcomputer AT89S52,is composed by the following functional modules : keyboard displaying ,sound  phonating. photoelectricity untouched switch，temperature gathering ,timing bell, 
According to the basic requirements of the subject ,our system stresses on the realization of time displaying and large screen displaying ,Furthermore ,we also extend the primary function ,adding new functions ,such as the single chip peripheral ports ,temperature gathering ,untouched ring-stop, scroll screen display, sound timing .and so on.
Adopting the idea of hardware-to-software, most of those functions are realized by softwares, which makes the electrocircuit more concise and the system more stable ,
The design achieved and even exceeded all the required basic technical indexes
Key words: chip microcomputer            large screen display system
          scroll screen display